OAL or OCW first?

[fremont]

Mikecr is a gunsmith and frequent scribe on this site. I begin all load testing with a moderate powder charge, and bullet right at kiss and then move in by .005" . When I am satisfied with that, I fine tune the charge .05 grs. at a time.

Got it; thanks

 

[SinCityJets]

Check out Mark Gordon's 6 part research story on this very topic. Pretty eye opening, and definitely not a mob mentality approach.

Bullet Jump Research: Executive Summary & Load Development Tips

This is the last post in a series of articles focused on bullet jump research that has been conduct...

precisionrifleblog.com

Chad

 

[Mc Fraser]

I've always used OCW with varying charge weights with a constant OAL (usually the longer of SAAMI max or .020" off the lands), but I was listening to the Modern Day Sniper podcast and their guest (can't remember his name) made an effective argument for using a constant (safe) charge weight with varying distances off the lands, e.g., start at .030" and go back to, say, .150".

Anybody tried both and have a clear favorite?

A LINK: https://www.longrangehunting.com/th...-from-berger-vld-bullets-in-your-rifle.40204/
Works with any & all bullets(not just Berger).

I'm not a gunsmith or scientist,,
If I'm different, it's that I'm of average intelligence and consider the notions of mobs(any) with skepticism.
This, because collective intelligence drops with numbers, so group judgement(mob thinking) is nearly always wrong.
View attachment 193085

Berger recommends this approach in their reloading book, the link above is exactly what is in the book as well.

 

[nicholasjohn]

A LINK: https://www.longrangehunting.com/th...-from-berger-vld-bullets-in-your-rifle.40204/
Works with any & all bullets(not just Berger).

I'm not a gunsmith or scientist,,
If I'm different, it's that I'm of average intelligence and consider the notions of mobs(any) with skepticism.
This, because collective intelligence drops with numbers, so group judgement(mob thinking) is nearly always wrong.
View attachment 193085

When I lived in Montana, I used to hear an expression when somebody said something REALLY stupid. They would say that he was "dumber than a hundred sheep." The more sheep there are in the flock, the dumber they act. Ditto for people, I've found out. Herd mentality is not a good thing.

 

[foul bore]

I am going to work a load for a 6.5 PRC soon. very helpful info posted. How many shots per group on seat depth test?

 

[Savage 12BVSS]

Used to use OCW first and then OAL and primers. Did it for years that way and you slowly arrive at your goal.

Then one day on this site I was reading thru a question that was asked same as in this thread and Mike went thru his method of starting with OAL first and then OCW and primer. Its faster to sort things out this way and I've adopted this method for load development now. You can always learn something new if you don't mind trying different methods.

 

[SinCityJets]

I just want to clarify one thing for people that may read this thread and maybe new to handloading. When people refer to OAL, they (hopefully) mean CBTO. OAL is irrelevant (unless above SAAMI or magazine specs) and will ABSOLUTELY vary from round to round even if components are identical. Any bullet you buy from even major top end manufacturers is 100%, without a doubt, going to vary in length by a few .00X's, bullet to bullet. Trying to make your OAL all the same is a fruitless tree, and will actually hurt your load development. Whereas, using identical components, practices and processes WILL lead to identical CBTO. And it is CBTO that will determine you're jump, not OAL.

Just wanted to clarify that point for those using this thread as a reference.

Chad

 

[kiwi49]

From here in New Zealand, I recall reading an article about primer brisance. What magazine or author I don't remember (old age kicking in), but there was a series of photos, showing how far/high, the primer flame exited from the neck opening of a primed ONLY case, sitting in a case holder. The primer was then activated by some sort of spring loaded pin. Camera shot was taken in a dark room, with an open shutter. The article/author was writing in a Peterson publication, when we could afford to buy American firearms magazines here. IIRC, magnum primers had the greatest/futherest flame front. No mention was made (but memory could be faulty here), of spring pressure, firing pin extrusion length or primer seating pressure/depth.

 

[Mikecr]

Similar testing photos from German Salazar: https://www.6mmbr.com/PrimerPix.html
There have also been snapshots of pressure produced from different primers, with weak correlations to primer mass.
Kelby did some testing to show better results from more consistent sear release.
It would be another thread to dig deeper into it. That could be a good one!

Unfortunately, pretty much all testing to date, that is available to us, is flawed in one or more ways.
Articles (gunwriters suck), merchandising of notions, bias confirmation from college professors, call to authority fallacies from competitors, and shade tree scientists, who might have hit on something (nobody knows).
None leading anywhere..